Frequency of Tuberculous Lymphadenitis among Sudanese Pediatric patients

Background: Tuberculosis (TB) is one of the major health challenges in many developing countries and in Sudan in particular. The aim of this study was to screen pediatric patients suspected with lymph Node (LN) TB for the presence of tuberculosis. 
Methodology: This study investigated retrospectively 42 LN biopsies taken from pediatric patients for evidences indicating the presence of Mycobacterium Tuberculosis (MT). Hematoxylin and Eosin (HE), Zielnelson (ZN), Immunohistochemistry (IHC) and Polymerase Chain Reaction (PCR) techniques were used for diagnosis. 
Results: For HE giant cell granuloma and caseation were evidenced in 33/42(78.6%), since epitheloid granuloma was evidenced in 9/42(21.4%). Positive ZN, IHC and PCR were indicated in 1/42(2.4%), 33/42 (78.6%) and 33/42(78.6%), respectively. 
Conclusion: pediatric TB is still prevalent in some parts of Sudan. More effective health strategies are urgently needed in Sudan, particularly in eastern Sudan to control the disease.

In developing countries there is still difficulty to differentiate tuberculosis lymphadenitis from other condition that cause lymph node enlargement (Bayazıt et al. 2004).The aim of this study was to screen pediatrics patients with lymphadenopathy for the presence of tuberculosis using different diagnostic technique.

MATERIALS AND METHODS
This retrospective study was carried out at the Histopathology Department of the National Laboratory in Sudan, including samples referred to the laboratory during the period from 2008 to 2011.

DISCUSSION
Sudan is a large country with miscellaneous population and history of civil conflict.Poverty levels are high with poor health delivery system.The country has a high burden of tuberculosis (TB) with an estimated 50,000 incident cases during 2009, when the estimated prevalence was 209 cases per 100,000 of the population (Ghada, et al. 2011).Incidence and prevalence of lymph node tuberculosis in Sudan is poorly documented.In 1992, Kheiry et al. drew attention to the fact that there were an increasing number of cases in Khartoum (Kheiry and Ahmed, 1992).
The findings of this study showing high frequency of pediatric Tuberculous lymphadenitis among patients attending with lymph node associated TB.In the present study out of (n=161) enlarged lymph node, 42 (26%) were pediatrics, the remaining were adult, these findings similar to previously published study from same country carried in 2003 by Aljafari et al. (2004).In a study from Sudan, a total of 670 patients were registered at Kassala hospital with clinical, laboratory and radiological evidence proven TB.Pulmonary TB accounted for 73.4% while extra-pulmonary TB was reported in 26.6% of all TB patients (Tajeldin, et al. 2012).
In this study 42 LN biopsies from pediatric patients was investigated retrospectively, using ZN, IHC and PCR.The age range was from 4 to 18 years.The majority of biopsies were from cervical LN (64.3%), these findings are in concordance with previously published results from this country carried by Aljafari et al. (2004) and study carried in USA by Talavera and Miranda (2001).In Yemen Hussain et al. (2001) reported similar results to ours.PCR using IS6110 oligonucleotides and IHC using anti 38 KD are the most recently applied methods in the diagnosis of tuberculous lymphadenitis (Baek, et al. 2000;Goel, et al. 2001).It proved to be highly sensitive and specific as was clearly demonstrated by this study.
Accordingly our PCR and IHC result showed higher sensitivity and specificity than Z.N stain in detection of lymph node tuberculosis, this finding such finding have reported by Juan Rodrguez et al. (2012) andTehmina Mustafa et al. (2006) also their results, combined with findings from a previous study carried by Honore, et al. (2001).
Lymphadenopathy due to tuberculosis was found in (78.6%) of Sudanese pediatric patients in this study using PCR and IHC which is much over than the report in 2012 from the same country by Bilal and Elshibly (2012) who reported a rate of (10%), and even much over than report of similar study from Greece by Papadopouli et al. (2009) who reported (12%) in 2009.This may be attributed to the low specificity and sensitivity of other technique and strategies for the diagnosis of the lymphadenopathy, that may have a false negative rate of would have been more yielding if combined with PCR, a costly tool of diagnosis in a developing country (Goel, et al. 2001).
In conclusion the risk of lymphadenopathy associated with LN tuberculosis was tremendously significant (P <0.0001).More effective health strategies are urgently needed in Sudan, since, TB continues to be an important public health problem in Sudan, particularly among younger population.

Fig. 1 :
Fig. 1: Description of the study population by Lymph node site